Constrained rotary vane compressors are known which utilize a rotor and an assembly of vanes rotating within a fixed, cylindrical stator housing. Such devices operate by the rotor having an axis of rotation offset from the axial centerline of the stator housing. Thus, compartments of varying volume are formed, defined by the regions between adjacent vanes, the stator interior, and the end walls of the stator.
Constrained rotary vane compressors differ from rotary vane compressors in that they include means for constraining the vanes from directly contacting the interior circumferential wall of the stator housing. Typically this is done by means of annular tracks formed in the stator end walls. The vanes include guide rollers projecting from either side and engaging said tracks.
The rollers and tracks constrain the vanes such that the distal edges of the vanes come in very close proximity to the interior wall of the stator housing, without actually contacting the wall, at particular points or regions to prevent the escape of fluid (i.e. gas or vapor) as the vanes rotate thereby performing the compression operation. There is a tendency for these vanes to vibrate and generate noise as they rotate, a characteristic rarely seen in unconstrained rotary vane compressors. In addition to the objectionable noise, the vibration increases wear and tear on the device. While many solutions to the noise/vibration problem in such devices have been employed with varying degrees of success, prior artisans have not heretofore satisfactorily solved the problem nor even appreciated at least one of the sources of the problem.